Ammonium Hydroxide Concentration Research Articles

Systematic Study of Reaction Conditions for Size-Controlled Synthesis of Silica Nanoparticles.

This study presents a reproducible and scalable method for synthesizing silica nanoparticles (SNPs) with controlled sizes below 200 nm, achieved by systematically varying three key reaction parameters: ammonium hydroxide concentration, water concentration, and temperature. SNPs with high monodispersity and controlled dimensions were produced by optimizing these factors. The results indicated a direct correlation between ammonium hydroxide concentration and particle size, while higher temperatures resulted in smaller particles with increased polydispersity. Water concentration also influenced particle size, with a quadratic relationship observed. This method provides a robust approach for tailoring SNP sizes, with significant implications for biomedical applications, particularly in drug delivery and diagnostics. Using eco-friendly solvents such as ethanol further enhances the sustainability and cost-effectiveness of the process.

Enhancing ammonia decomposition in ammonium hydroxide/diesel emulsion through hybrid nanocomposite and optimization for improved and greener combustion

In this study, a hybrid nanocomposite was synthesized and characterized to intensify ammonia decomposition in ammonium hydroxide (AH) emulsified diesel fuel. The optimal concentrations of AH and zinc oxide/carbon nanotube (ZnO/CNT) nanocomposite in diesel fuel were evaluated using response surface methodology for effectual and greener combustion. The range of AH concentration was varied from 10 % to 30 %, and ZnO/CNT nanocomposite concentration ranged from 50 ppm to 150 ppm in diesel fuel. Validation experiments were performed to confirm the optimized parameters’ competence compared to regular diesel fuel (RDF). Fourier Transform Infrared and X-ray Diffraction analyses verified successful ZnO/CNT nanocomposite synthesis with desired structural and chemical properties. Optimization results indicated that an 17.2 % volume concentration of AH and 82.3 ppm of ZnO/CNT nanocomposite in RDF yielded efficient combustion with reduced emissions. Validation results showed that the inclusion of 17 % AH in RDF decreased engine brake thermal efficiency (BTE) by 11.1 % and increased brake specific fuel consumption (BSFC), hydrocarbon (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) emissions by 11.3 %, 9.1 %, 9.9 %, and 3 %, respectively. Furthermore, the presence of the nanocomposite (82.3 ppm) enhanced BTE by 10.1 % and reduced BSFC, HC, CO, and NOx emissions by 6.9 %, 6.2 %, 6.9 %, and 5.9 %, respectively. The advancements in fuel additives, such as ZnO/CNT nanocomposites in AH emulsified diesel fuel, have the potential to create more fuel-efficient and cleaner diesel engines. These improvements can significantly contribute to sustainable energy solutions.

Enhancing energy and environmental metrics of aqueous ammonia emulsified diesel fuel using carbon-metal oxide nanocomposites: An experimental study

The study explores the impact of a zinc oxide (ZnO) induced carbon nanotube (CNT) nanocomposite on ammonia decomposition in aqueous ammonia (AA) emulsified diesel fuel, while evaluating performance and emissions. Functionalized CNTs induced with ZnO underwent structural and surface morphology analysis. Different concentrations of ammonium hydroxide (5 % and 10 %) were mixed with plain diesel fuel (PDF), and 100 ppm of ZnO/CNT was blended with 10 % AA emulsified fuel. Fuel performance was assessed under various brake power conditions compared to PDF. The results demonstrate that the absorption of latent heat by ammonia and its higher decomposition energy result in a longer ignition delay, thereby increasing peak in-cylinder pressure and net heat release rate. The post-combustion reaction of AA emulsified fuels contributes to increased brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC), hydrocarbon (HC), carbon monoxide (CO), and smoke opacity. However, the dispersion of nanocomposite in AA emulsion enhances the catalytic effect and promotes ammonia decomposition, resulting in combustion characteristics similar to PDF. Notably, there is an observed improvement in BSFC by 8.1 % and BSEC by 10.9 %, respectively. Furthermore, emission metrics such as oxides of nitrogen, HC, CO, and smoke opacity decrease by 4.5 %, 18.8 %, 11.4 %, and 5 %, respectively.

Selective separation of Fe and Ga from Al-containing HNO3 leach liquor using cupferron: Efficiency, mechanism, and regeneration

Coal gangue and fly ash are typical coal-based solid waste and can be considered as Al and Ga resources. The HNO3 leaching technology was proposed by our team for the economical and efficient co-extraction of Al and Ga, whereas the separation and recovery of metal elements became a challenge due to the variety of co-existing ions in the leach liquor. In this work, a Ga-Fe iso precipitation strategy with cupferron (C6H9N3O2) as a selective precipitant followed by regeneration and circulation of cupferron was proposed. The feasibility of the technique was assessed by thermodynamic analysis. The systematic precipitation experiments showed that 99.05 % of Ga, 99.89 % of Fe, and 4.74 % of Al were transferred into the complex precipitation product at optimal conditions. And the separation factor of Ga vs. Al and Fe vs. Al were as high as 2101.74 and 17713.93, respectively. The precipitation mechanism was revealed via a suite of characterization methods to be the chelation of metal ions and cupferron, with the terminal oxygen (N = O) and hydroxyl oxygen (O–H) as ligating atoms. The regeneration rate of cupferron reached 81.28 % with an ammonium hydroxide (NH3·H2O) concentration of 8 mol/L. And the circulation experiment demonstrated the excellent performance of the regenerated cupferron. This work provides a new insight into the deep removal of Fe and the enrichment of Ga from the acidic solution.

Synthesis of Hierarchical Superhydrophilic/Superhydrophobic Nanostructured Surfaces for Oil/Water Separation

AbstractSurface wetting, the phenomenon where a liquid spreads or adheres to a solid surface, plays a crucial role in both natural and technological fields. This study focuses on elucidating the relationship between surface properties and wetting behavior, emphasizing the significance of hierarchical structures. A 3D hierarchical structure is created by controlling shape and size through electroplating and chemical reactions, adjusted by current intensity, ammonium persulfate, and ammonium hydroxide concentrations. This modification is achieved by modifying the surface's chemical properties. This control directly impacted the surface wetting properties, providing a means to regulate wetting behavior by altering surface structure. Through control of surface chemistry, a superhydrophilic surface is able to successfully create with a contact angle of 0° and a superhydrophobic surface with a contact angle of 171.3.

A novel approach to the green synthesis of zinc oxide nanorods using Thymus kotschyanus plant extract: effect of ammonium hydroxide and precursor concentration

This research introduces a pioneering green method for synthesizing zinc oxide nanorods (ZnO NRs) on a glass substrate using Thymus kotschyanus plant extract. The study delves into the intricate effects of ammonium hydroxide and precursor concentrations on the morphology, size, alignment, and crystalline structure of ZnO NRs. Through systematic experimentation, it was found that specific concentrations of these substances play vital roles in the formation and properties of the nanorods. Notably, a low concentration of the precursor coupled with a high concentration of ammonium hydroxide led to well-aligned hexagonal ZnO NRs with a remarkable aspect ratio. Variations in these concentrations were also found to influence the length, diameter, and alignment of the nanorods. The findings were corroborated using a diverse array of analytical techniques, including transmission and scanning electron microscopy, x-ray diffraction, UV–vis spectroscopy, and energy-dispersive x-ray analysis. The UV–vis spectra provided further insights into the optical properties and band gap energy of the ZnO NPs, while EDX analysis confirmed the elemental composition. This work represents a significant advancement in eco-friendly nanomaterial synthesis, providing detailed insights into the controlled fabrication of aligned ZnO NRs. Its innovative approach and extensive investigation into influencing factors make it a valuable contribution to the field of nanoscience.

Influence of Chemical Cleaning Procedures and Thermal Oxidation Processes on the Uniformity of MOS Gate Oxides on Abrupt Steps on Silicon Surfaces

This work analyzes the influence of some chemical steps used in standard cleaning recipes on the surface micro-roughness of silicon wafers. The effect of varying the ammonium hydroxide concentration in the NH4OH: H2O2:H2O solution was studied and silicon wafer micro-roughness was characterized by atomic force microscopy technique at different scans of 1µmx1µm. Based on the results, it was possible to point the condition to obtain low surface micro-roughness for NH4OH-based solutions with the lowest NH4OH content before the growth of gate oxides. Following, it silicon-oxide thin films were grown onto periodic rectangular shapes, 100 nm in height, obtained by localized plasma etching on silicon wafer surfaces. Silicon oxides (SiO2), about 4.5 nm thick, were grown in ultrapure dry-O2 or pyrogenic (O2 + H2) environments in order to compare the planar uniformity and the grade of coverage at the step edges of rectangular shapes defined onto silicon surfaces. Pyrogenic and conventional oxidation at 850 oC allowed one to obtain gate oxides on 100 nm-stepped silicon surfaces with high dielectric breakdown field (>10 MV/cm), good planar uniformity and conformal coverage at the step edges. The impact of this result is now the feasibility of fabricating good-quality gate oxides for surrounding gate transistors (SGT’s) and texturized MOS solar cells.

A Combined Approach for the Treatment of Textile Dye Bath Effluent Using CO2 Gas

In this study, baking soda extraction from textile dye bath effluent has been investigated. The novel notion of employing amino acid additions to improve the standard Solvay method and thereby boost the efficiency of Na+ recovery has been investigated. Glycine, L-arginine, and L-alanine are three amino acid additions examined for their effect on enhancing Na+ recovery, and the best-suited additive is chosen. The dumping of brackish dye bath effluent, which has a high percentage of sodium chloride, causes textile dye baths from the textile industry. The primary goal was to remove Na+ (sodium) from the effluent using carbon dioxide gas, which has environmental benefits. Carbon dioxide (CO2) is the most common greenhouse gas, trapping heat and raising global temperatures, therefore contributing to climate change. The Solvay process is used to transform Na+ in salty wastewater into a valuable product. The effect of different operating variables such as NH4OH (ammonium hydroxide) concentration, reaction temperature, carbonation time, and carbon dioxide gas flow rate on bicarbonate production was investigated. Maximum sodium recovery of about 68 percent is attained under optimal circumstances. When compared with the regular Solvay process, the modified Solvay method has a greater recovery efficiency (33 percent). Amino acid addition (arginine) improved conversion efficiency while also lowering the process’s ammonia need.

The potential impact of replacing nitrate with ammonium hydroxide in microalgae production on the biomass productivity and CO2 utilization efficiency

Ammonium hydroxide has many advantages as a CO 2 absorbent compared with other amine solutions in Carbon Capture, Utilization and Storage. In this work, the use of ammonium hydroxide was suggested to replace the nitrate as an alternative nitrogen source and to enhance the CO 2 utilization and biomass production during microalgae cultivation. Abiotic absorption experiments showed that the CO 2 absorption capacity of culture medium increased with the increase of ammonium hydroxide concentration, and it kept consistent with different kind of CO 2 absorbents. Consumption curves for sodium nitrate and ammonium hydroxide were built from batch cultivation experimental data and it was found that the microalgal cells had faster growth rates when these nutrients concentrations were kept at low levels (2 mmol/L and 4 mmol/L, respectively). In the fed-batch cultures under both indoor and outdoor operations, the maximum biomass concentration and carbon utilization efficiency using ammonium hydroxide as a nitrogen source was much higher than that of using sodium nitrate as a nitrogen source. By using pH-regulated CO 2 supplementation, the pH of the microalgae culture medium was maintained within the neutral or slightly alkaline range. Thus, the volatilization of ammonium hydroxide was negligible. These results indicated that replacing nitrate with ammonium hydroxide could be a promising approach to increase CO 2 utilization efficiency and to reduce production costs in microalgae cultivation. • Replacing sodium nitrate with ammonium hydroxide as the nitrogen source was first proposed in microalgal cultivation. • Biomass concentration and carbon utilization efficiency using ammonium hydroxide as nitrogen sources were achieved by 2.35 g/L, and 114.93%. • A 32.8 % increase in the biomass productivity using ammonium hydroxide compared to that of sodium nitrate under outdoor conditions. • Ammonium hydroxide could be a cheaper source of nitrogen that can enhance CO 2 utilization by microalgae.

Insight on the Dependence of the Drug Delivery Applications of Mesoporous Silica Nanoparticles on Their Physical Properties

SummaryMesoporous silica nanoparticles (MSNs) are fascinating due to their interesting properties and applications.PurposeThe optimization of MSNs for drug delivery applications was achieved by preparing different formulations of MSNs using different concentrations of ammonium hydroxide (NH4OH) (0.7, 1.4, 2.8, 4.2, and 5.6 mg/ml for MSN1, MSN2, MSN3, MSN4, and MSN5, respectively).MethodsIn the synthesis of MSNs, NH4OH was used as a catalyst while tetraethyl orthosilicate were used as a source of silica. Transmission electron microscopy (TEM) image revealed a linear increase in the size of the formed MSNs with increase in catalyst concentration. TEM images showed that all investigated nanoparticles were dispersed and spherical (changed to oval on addition of higher concentration of NH4OH).ResultsThe hydrodynamic sizes of prepared MSNs were (64.18 ± 6.8, 90.46 ± 7.1, 118.98 ± 7.01, 152.7 ± 1.7, and 173.9 ± 9.36 nm for MSN1, MSN2, MSN3, MSN4, and MSN5, respectively) assessed using the dynamic light scattering (DLS) technique. The negative values of zeta potential indicated high surface stability of the formed MSNs. N2-isotherm revealed that the pore volume of MSNs decreased with increase in the size of MSNs. In vitro drug release showed that all MSNs exhibited high encapsulation efficiency of doxorubicin. The encapsulation efficiency were 92.2%, 82.8%, 72.2%, 72.1% and 71.9%for MSN1, MSN2, MSN3, MSN4, and MSN5, respectively. ConclusionMSN1 and MSN2, with sizes of 64.18 ± 6.8 and 90.46 ± 7.1 nm, pore volume of 0.89 and 0.356 cc/g, encapsulation efficiency of 92.2% and 82.8%, and adequate drug release profiles, were probably the best choices for a drug carrier in drug delivery applications.

Synthesis of ZnO nanoparticles using Sapindus rarak DC fruit pericarp extract for rhodamine B photodegradation

Zinc oxide Nanoparticles (ZnO NPs) were successfully synthesized via a green synthesis route by using Sapindus rarak DC fruit aqueous extract (SFE). In addition, a comparative evaluation of ZnO NPs synthesis was conducted using isolated saponins (SN) obtained from SFE. This was performed to observe the role of saponins in the synthesis of ZnO NPs as they could act as a capping agent as well as control the morphology and size of the particles. In this work, various concentrations of ammonium hydroxide (NH4OH) were used in the ZnO NPs synthesis with the presence of SN. This was conducted with the aim to understand the effects of hydroxide ions addition to the resulted products of the synthesis. The samples were characterized using XRD (X-Ray Diffraction), UV–vis DRS (UV–vis Diffuse Reflectance Spectroscopy), and TEM (Transmission Electron Microscopy). The results show that the ZnO NPs with smaller and more faceted particles were obtained for those synthesized using SFE as compared with the ones synthesized using SN and with the addition of NH4OH. The ZnO NPs synthesized using SFE exhibited the best performance photocatalyst for the degradation of Rhodamine B up to 99.7% with 120 min of reaction time.

Fabrication and Characterization of Hydrophobic Cellulose Nanofibrils/Silica Nanocomposites with Hexadecyltrimethoxysilane.

Cellulose nanofibrils (CNFs) have attracted much attention because of their renewability and potential biocompatibility. However, CNFs are extremely hydrophilic due to the presence of a large number of hydroxyl groups, limiting their use as a water-resistant material. In this work, we controlled the adsorption behavior of silica nanoparticles on the surface of CNFs by adjusting the synthesis conditions. The silica nanoparticle size and packing efficiency on the CNF surface could be controlled by varying the ammonium hydroxide and water concentrations. In addition, hexadecyltrimethoxysilane (HDTMS) was successfully grafted onto CNF or CNF/silica nanocomposite surfaces, and the quantitative content of organic/inorganic substances in HDTMS was analyzed through XPS and TGA. The HDTMS-modified CNF/silica nanocomposites were more advantageous in terms of hydrophobicity than the HDTMS-modified CNF composites. This is because the silica nanoparticles were adsorbed on the surface of the CNFs, increasing the surface roughness and simultaneously increasing the amount of HDTMS. As a result, the HDTMS-modified CNFs showed a water contact angle (WCA) of ~80°, whereas HDTMS-modified CNF/silica nanocomposites obtained superhydrophobicity, with a WCA of up to ~159°. This study can provide a reference for the expansion of recyclable eco-friendly coating materials via the adsorption of silica nanoparticles and hydrophobic modification of CNF materials.

Study on wet etching of dummy polysilicon in narrow pattern gap using alkaline solution

The polysilicon etching in a patterned wafer is an important process. In this process, the polysilicon must be completely removed without damaging the gaps made from SiO2 or Si3N4. In this study, a wet etching method was used to completely remove polysilicon while reducing it to SiO2. Alkaline solutions known as etching polysilicon, i.e., ammonium hydroxide (AH) and tetramethylammonium hydroxide (TMAH), were used. The etch rate was confirmed according to various factors such as temperature, chemical concentration, and rotation speed, but the etch rate was most affected by the chemical concentration. Accordingly, the concentration of hydroxide ions was the main factor for etching polysilicon. The etch rate of TMAH had the same tendency as AH for various factors, but the results indicated a difference of approximately eight times (1744 Å/min for TMAH and 217 Å/min for AH, condition: 6 wt%, 70 °C, 100 RPM). The electrical double layer (EDL) was calculated by using the pH, which was measured at each concentration of AH and TMAH solution, to etch the polysilicon in the narrow gap. The EDL was affected by the hydroxide concentration; thus, the TMAH solution etched the polysilicon in the narrow gap better than AH did. Furthermore, the experiment was conducted using an additive that could decrease the SiO2 etch rate and increase the selectivity between polysilicon and SiO2. Although the etch rate of polysilicon was reduced by 23%, the etch rate of SiO2 was also reduced by 43%.

Selective Chelating Resin for Copper Removal and Recovery in Aqueous Acidic Solution Generated from Synthetic Copper-Citrate Complexes from Bioleaching of E-waste

This research focused on batch experiment using a new generation of chelating resins via an ion exchange process to describe the metabolic adsorption and desorption capacity onto iminodiacetic acid/Chelex 100, bis-pyridylmethyl amine/Dowex m4195, and aminomethyl phosphonic/Lewatit TP260 functional groups in bioleaching. The results showed that Dowex m4195 had the highest performance of adsorption capacity for copper removal in both H+-form and Na+-form. Results for Lewatit TP260 and Chelex 100 revealed lower adsorption performance than results for Dowex m4195. The investigation of desorption from chelating resins was carried out, and it was found that 2 M ammonium hydroxide concentration provided the best desorption capacity of about 64.86% for the H+-form Dowex m4195 followed by 52.55% with 2 M sulfuric acid. Lewatit with 2 M hydrochloric acid gave the best desorption performance in Na+-form while Chelex 100 using hydrochloric at 1 M and 2 M provided similar results in terms of the H+-form and Na+-form. As aspects of the selective chelating resins for copper (II) ions in aqueous acidic solution generated from synthetic copper-citrate complexes from bioleaching of e-waste were considered, H+-form Dowex m4195 was a good performer in adsorption using ammonium hydroxide for the desorption. However, chelating resins used were subsequently reused for more than five cycles with an acidic and basic solution. It can be concluded from these results that selective chelating resins could be used as an alternative for the treatment of copper (II) ions contained in e-waste or application to other divalent metals in wastewater for sustainable water and adsorbent reuse as circular economy.

High-yield production of secoisolariciresinol diglucoside from flaxseed hull by extraction with alcoholic ammonium hydroxide and chromatography on microporous resin

This study used alcoholic ammonium hydroxide to directly hydrolyze and extract secoisolariciresinol diglucoside (SDG) from flaxseed hull in a one pot reaction. The optimal extraction conditions, including the concentration of ammonium hydroxide, extraction time, and temperature, were examined in single factor experiments, followed by response surface methodology (RSM) with 3-level, 3-factor Box-Behnken experiments. As a result, the optimal extraction conditions were determined as follows: material-liquid ratio 1:20, percentage of reagent ammonium hydroxide (25–28% of NH3 in water) in ethanol 33.7% (pH = 12.9), extraction time 4.9 h, and extraction temperature 75.3 °C. Under these conditions, the yield of SDG, as measured by ultra-high-performance liquid chromatography-mass spectrometry, was 23.3 mg/g, consistent with the predicted content of SDG in flaxseed hull (23.0 mg/g). Further, 30.0 g of pulverized flaxseed hull was extracted under the optimal conditions, and the extract was subjected to a single run of macroporous resin chromatography to obtain 772.1 mg of a fraction with an SDG content exceeding 76.1%. Subsequent chromatography on Sephadex LH20, yielded 602.8 mg SDG of 98.0% purity, and the yield was 20.1 mg/g (2.0%) from flaxseed hulls. Thus, one-pot hydrolysis and extraction of SDG using alcoholic ammonium hydroxide is simple, and of high-yield.Graphical abstract

Effect of varying the concentration of sulphuric acid and ammonium hydroxide on the release of cellulose from isolated cell wall component of corn cob

The scarcity and high price associated with fossil fuel has urged countries to research resources for alternative energy sources. Biofuels like bioethanol produced from lignocellulosic biomass (corn cob) were considered potential alternative. Cellulose composition from isolated cell wall material of corn cobs was investigated under two different pre-treatments using H2SO4 and NH4OH at varying concentrations of 5%, 10%, 20%, 30% and 40%. Cell wall not treated acted as control. Colorimetric anthrone-assay followed by absorbance reading at 625nm revealed that glucose is present in reasonable amount in corn cob. The analysis of variance (ANOVA) indicated significant differences among pre-treated compared to untreated (Control) corn cob samples at p≤0.05. Acid pre-treatment showed better glucose yield compared to alkali pre-treatment with results revealing 20% (19.37µg/ml) H2SO4 to be the optimal concentration producing highest glucose yield. The study reveals the potential of corn cob as a lignocellulosic feed stock for biofuel production.

Clean Conversion of Aqueous Ammonia Using a Solid Oxide Cell

Ammonia (NH3) is present as an impurity in coke oven gas (COG), which is a by-product of coke-making processes required for the manufacture of steel. Due to its highly corrosive and toxic nature, ammonia is removed from COG by water scrubbing processes generating a highly problematic aqueous waste stream containing ammonia (19 vol%), hydrogen sulphide (4 vol%), carbon dioxide (14 vol%) and tars. At Tata Steel Port Talbot (South Wales, UK) alone, approximately 44,000 m3 of COG and 264 kg of ammonia are produced every hour. This is currently disposed of via incineration, contributing to air pollutant emissions and wasting a valuable and useful resource.It is well known that solid oxide fuel cells (SOFCs) can convert ammonia gas to electrical power and heat when operating in fuel cell mode [1-3]. In this work, conversion of a liquid aqueous ammonium hydroxide solution (35%) using a commercially available anode-supported button cell was investigated in fuel cell and electrolysis mode. This mixture served as a basic initial simulation of the waste ammonia streams produced from coke-making processes. The electrical performance of the cell was characterised using I-V curves and electrochemical impedance spectroscopy, and the output gases of the cell were measured in real-time using quadrupole mass spectrometry (QMS).The QMS data show the ammonia decomposed to nitrogen and hydrogen at the open circuit voltage (OCV). In fuel cell mode, the cell utilised hydrogen to produce electrical power. I-V curves were measured showing the effect of the ammonium hydroxide solution on cell efficiency compared with deionised water (see figure). Increasing the deionised water flow rate decreased the OCV considerably and substantially increased the concentration losses; under a 20/80 vol% H2/H2O mixture, the cell produced 50-80% of the current yielded under pure H2. With the ammonium hydroxide solution, OCV and concentration losses were affected much less as the flow rate of the mixture was increased, indicating conversion of ammonia into electrical power with high efficiency. The I-V curves and electrochemical impedance spectra indicated very low activation losses.In electrolysis mode, the presence of ammonium hydroxide decreased performance and this was attributed to the decreased presence of H2O, which the I-V curves (see figure b) and impedance spectra show increased the activation and concentration losses. However, the QMS data have demonstrated that electrolysis of H2/NH4OH mixtures increases the H2 production by a factor of approx. 2.3 and yields a gas mixture composed of approx. 87 vol% H2 balanced in N2, with no NO x production observed.

The Effect of Resin and NH4OH Addition in The Making of Ammonium Silica Fertilizer from Geothermal Sludge

Geothermal sludge is a waste product from geothermal where it contains SiO2 which can be used as fertilizer. In this study, the making of silica ammonium fertilizer was carried out by taking salicy acid from geothermal sludge by extracting and adding resin which was then modified with NH4OH addition. Extraction was done using 1000 ml of KOH 1 N to dissolve 60 grams of Geothermal Sludge. Resins are added with variations in resin weight, namely, 5, 10, 20, 30, and 40 grams. NH4OH was added with variations in concentrations namely 3, 6, 9, 12 and 15% with a ratio of filtrate and NH4OH solution of 1: 1. The resulting ammonium silica inorganic liquid fertilizer products were analyzed for free silica and ammonia levels. The results of this study indicate that the levels of free silica and ammonia are influenced by the weight of the resin used and the concentration of ammonium hydroxide mixed. From the results of the research, it was found that inorganic silica liquid fertilizer with the highest SiO2 content in ammonium silica liquid fertilizer occurred when adding 20 grams of resin with the addition of NH4OH with a concentration of 15% which was 1,831.87 mg / L while the highest NH3 content in fertilizer liquid ammonium silica occurs when adding 40 grams of resin with the addition of NH4OH with a concentration of 15% which is equal to 252,312.80 mg / L.

Statistical analysis of the influence of synthesis conditions on the properties of hierarchical zeolite Y

Commercial zeolite USY (CBV500, Si/Al = 2.6) was dealuminated with oxalic acid, desilicated with ammonium hydroxide assisted by cetyltrimethylammonium bromide, and acid washed with lactic acid for obtaining hierarchical zeolite Y. The samples were characterized by X-ray diffraction, N2-physisorption, temperature programmed desorption of NH3, transmission electronic microscopy and diffuse reflectance infrared Fourier transform spectroscopy Ppyridine adsorption. A central composite experimental design was used for obtaining the influence of the concentration of the three solutions used in each step of the synthesis, on the relative crystallinity (%RC), mesopore volume (Vmeso), and total acidity of the synthesized materials. All the materials conserved the %RC and total acidity between 51-89% and 51–80%, respectively; modified materials showed an increase of up to 300 m2/g of external surface area and 0.17 cm3/g of the Vmeso with respect to the CBV500 sample. The statistical analysis showed that all the properties are influenced by oxalic acid concentration, whereas ammonium hydroxide concentration affects Vmeso, and lactic acid concentration affects %RC and total acidity in the modified samples. According to the optimization of the process, the material synthesized and labeled as MZ-OP, showed a %RC = 82%, Vmeso = 0.21 cm3/g, and total acidity of 1.430 mmol/g. The catalytic cracking of n-dodecane was tested over CBV500, MZ-OP, and MZ-10-100-500 and the obtained conversion at 300 min was 65%, 95% and 82%, respectively. Deactivation rate of the modified samples was significantly lower than the values obtained with CBV500, showing that the modified samples were more stable under tested reaction conditions.

Influence of Ammonia Stripping Parameters on the Efficiency and Mass Transfer Rate of Ammonia Removal

This study analyzed the influence of different ammonia stripping parameters on ammonia removal efficiency and mass transfer rate. Ammonia stripping was performed on two devices, a column and a packed tower, with artificial ammonium hydroxide wastewater. First, ammonia concentration and pH were varied in a column without liquid circulation. At the same pH, the removal efficiency and mass transfer rate were constant, irrespective of initial ammonia concentration. When pH was increased, the ammonia fraction also increased, resulting in higher removal efficiency and mass transfer rate. Second, the effects of stripping were assessed using a packed tower with fluid circulation. The ammonium hydroxide concentration did not affect the removal efficiency or mass transfer rate. Furthermore, at apparatus liquid-gas ratios of 26.8–107.2 L/m3, a lower liquid-gas ratio led to increased ammonia removal efficiency and mass transfer rate. Conversely, the lower the liquid-gas ratio, the greater the air consumption. In conclusion, considering the removal rate and volume of air supply, the range of optimal liquid-gas ratio was determined as 26.8–53.6 L/m3. In particular, the 26.8 L/m3 condition achieved the best ammonia removal rate of 63.0% through only 6 h of stripping at 70 °C and pH 8.5.